Model for formation of amicronucleate Tetrahymena. One or more errors of macronuclear development in a macronucleus result the failure to rearrange a functional mat gene, resulting in the loss of sex. Either simultaneously or through subsequent reproduction, the macronucleus acquires the essential somatic (oral) function of the MIC (see text), and eventually the MIC is lost. The resulting asexual amicronucleate is capable of independent evolution through mutation and macronuclear assortment.
Doerder BMC Evolutionary Biology 2014 14:112 doi:10.1186/1471-2148-14-112